Copper complexes of dianisidine disazo dyes



Patented Mar. 16, 1948 COPPER COMPLEIES OF blANISIDINE DISAZO DYES Joseph Francis Laucius, Wilmington, Del., and William W. Williams, Albany, N. Y., assignors to E. I. du Pont de Nemours & Company, Wilmmgton, Del., a corporation of Delaware No Drawing. Application January 11, 1944, Serial No. 517,894

6 Claims. 1

This invention relates to new dyestuffs which are substantive to cellulosic and to silk materials. In particular it relates to a class of coppered azo dyes made from azotized dianisidine coupled to a naphthol sulfonic acid.

In 1917 Gessler in U. S. P. 1,157,525 disclosed a number of pigments among which is a laked disazo compound resulting from the coupling of 2,6-naphthol-sulfonic acid and tetrazotized dianisidine, coppered with copper sulfate solution.

It is an object of this invention to prepare substantive dyes which are distinguished from the lakes of Gessler in being water-soluble textile dyestufis. Other objects of the invention will be apparent or disclosed hereinafter.

The objects of the invention are accomplished,

generally speaking, by coupling tetrazotized di-.

anisidine to two moles of Schaefiers salt, or certain other naphthol mono-sulfonic acids, and reacting the product with ammoniacal copper sulfate, or some other copper yielding compound, at a temperature high enough to split the methyl group ofi the dianisidine nucleus. In place of Schaeflers salt, 1-naphthol-5-sulfonic acid or 1- naphthol-3-sulfonic acid may be employed as the coupling component, yielding respectively excellent blue and violet colors. The term Schaeifers salt as used in this specification and claims refers.

to 2-naphthol-6-sulfonic acid.

In the practice of the invention the dyes are treated in substance with copper yielding agents, such as copper sulfate, copper acetate, and copper ammonium sulfate in aqueous solution, at temperatures which split oif the methyl groups, for instance at temperature from 50-150 C. Superatmospheric pressure may be employed but is not usually necessary.

HOtS

dianisidine= (naphthol mono-sulfonic acid)2 colors. For instance, Color Index 502, dianisidine (1-naphthol-4-sulfonic aCid)2 is weaker after coppering than before, and the corresponding dyestuff from dianisidine= (2-naphthol-7-sulionic -acid)2 is still weak after coppering.

In the following example parts are expressed in parts by weight and the proportions employed are exemplary.

Example To 4,000 parts water is added with stirring 244 parts dianisidine (3,3-dimethoxy-4,4'-diaminodiphenyl), 183 parts hydrochloric acid as a 22% solution and 138 parts sodium nitrite as a 30% aqueous solution with the temperature being maintained at 15-20 by addition of ice. The solution is stirred one-half hour and then added with stirring to a solution containing 518 parts sodium Z-naphthol-G-sulfonate, '72 parts sodium hydroxide, parts sodium carbonate and 500 parts of ice. The reaction mixture is stirred an hour or more. A slight excess of 2-naphthol-6- sulfonic acid is present, due to a slight decomposition of the tetrazo compound. Alkalinity sufficient to give a strong spot test on Brilliant Yellow paper is maintained until the coupling is complete. The mixture is heated to 80-85"; 625

parts crystalline copper sulfate, 500 parts ammonia as a 28% solution, and 6000 parts of water are added. The heating is maintained for 16 hours and the pH is maintained at 9.0-9.5 by addition of ammonia. The charge is then salted 5%, filtered and the press cake dried. The dyestuff is represented in its acid form by the following formula:

It is a dark powder, soluble in water, and dyes cellulosic and silk fibers by usual methods in a blue-violet shade very fast to light.

When l-naphthol-5-sulf0nlc acid is substituted for Z-naphthol-G-sulfonic acid in the above, there results a dye which dyes cellulose textile material a blue shade very fast to light. Similarly, substitution of 1-naphthol-3-sulfonic acid for 2-naphthol-6-sulfonic acid leads to a dye which colors cellulosic textile material a strong violet shade fast to light.

The dyestufis produced by this invention are much improved in quality over the nearest colors 3 4 of the prior art, show astonishing strength iol- 5. The process which ,comprisesheating in amlowing the coppering, and are not the compounds moniacal medium with an agent yielding copwhich were produced by Gessler. per, the compound 3,3'-dimethoxy-4,4-diamino- AS y apparently Widely difielent embodic dipheny1= A z which is coupled in alkaline ments of this invention may be made without 'de- :5 medium and in which A is one of a group com parting mm the and w it sisting or Z-naphthoi-G-sulfonic acid, l-naphto be understood that the invention is not limitb acid and l naphthol fi sulfonic gggg g f fg sg z gggg gggg thereof except as acid, said heating being at a temperature which We claim: splits the methyl group from the dianisidine nu- A symmetrical watebsolublecoppel. complex cieus and forms a water-soluble copper complex represented by the for ul having aflinity for cellulosic fibers.

16, The process which comprises heating a disazo compound represented by the formula 3,3'-dig g l methoxy-4,4-diamino-diphenyl= (A)2 in which 0 A is one of a group consisting of 2-naphthol-6- wherein R is the radical of one of the group con- 51111501110 ac d, 1-naphthol-3-sulfonic acid,.and 1- sisting of2-naphtho1-6-su1f0nic acid, 1-naphthol- 'naphthol-5-su1fonic id with a soluble com- 3-sulfonic acid and l-naphthol-fiesulfonic acid. pound yielding copper, at a temperature which 2. The Water-soluble textile dyestufi repredisplaces the methyl groups from the diphenyl sented in its acid form by the formula nucleus and forms a water-soluble copper com- N N N N I i i i i i-o oi'1- -Cl. l'0- 3. The water-soluble textile dyestufi repreplex having affinity for cellulosic textile fiber. sented in its acidform by the formula JOSEPH FRANCIS LAUCIUS.

0 Cu-O O-Cu0 WILLIAM W. WILLIAMS.

I v I I OO$ REFERENCES CITED SOZH H015- The following references are of record in the 4. The water-soluble textile dyestufi reprefile of this patent:

UNITED STATES PATENTS sented in its acid form by the formula Number Name Date 40 1,921,337 Wiedemann ct a1. Aug. 8, 1933 o Bu-O O-( u-0 1,157,525 Gess1er Oct. 19, 1915 5 t v 1,951,580 Delis et a1 May 8,1934 N=N V 2,294,426 Scully Sept. 1, 1942 FOREIGN PA'IENTS Number Country Date Rois 166,220 Switzerland Mar. 1, 1934 

